The LPG Bioinformatics Core Group performs two roles. The first is to support the activities of the LPG through data analysis and management, as well as by facilitating communication within the Laboratory. The second is to provide resources for use by the wider cancer research community. The Core Group provides technical support to researchers within the LPG. Members of the Core worked with the Struewing and Lee labs to design a cancer gene resequencing microarray, which will be used to identify novel mutations in 79 loci associated with cancer. They collaborated with the Zhang group to produce gene-based chip definition files for Affymetrix human and mouse gene expression arrays. The Core Group also provides technical, analytic and management support for Buetow lab liver and breast cancer projects. Members of the Core Group participate in the National Cancer Institute's Genetic Annotation Initiative (GAI), which expands the collection of gene-based genetic analysis reagents for cancer research. The GAI has identified more than 40,000 candidate human single nucleotide polymorphisms (SNPs) by analyzing publicly available expressed sequence tag chromatograms. Over 16,000 candidate mouse SNPs have been identified. The GAI has validated more than 8,000 human SNPs via mass spectrometry. The Bioinformatics Core Group works with members of the LPG to develop and maintain a variety of web-based tools for cancer research. Integrated genetic and physical SNP maps, a Java-based tool for viewing candidate SNPs in the context of EST assemblies, reagent information (including PCR primers and extension primers) and a SNP search engine are available at http://lpgws.nci.nih.gov/GAI/. A browser that displays polymorphisms in the context of mRNA sequences, open reading frames, protein motifs and three-dimensional protein domain structures is accessible at http://lpgws.nci.nih.gov/cgi-bin/GeneViewer.cgi/. Annotation for Affymetrix human and mouse GeneChip expression array sets are available at http://lpgws.nci.nih.gov/cgi-bin/AffyViewer.cgi.The Core Group developed and maintains a web-based tool for accessing the Quantitative PCR Primer Database created by the Gene Expression Laboratory at NCI-Frederick. Through this search engine, http://lpgws.nci.nih.gov/cgi-bin/PrimerViewer, researchers can retrieve information about PCR-based reagents for measuring the expression of human and mouse genes. The database includes 2055 human and 290 mouse primer sets.The Bioinformatics Core Group is working with Science Applications International Corporation to customize and extend the open source laboratory information management system caLIMS. lpgLIMS will include adaptors for Affymetrix gene expression and mapping microarrays and will feature improved ease of installation.